Yes, DKA Can Occur With Normal Ketones
Yes, diabetic ketoacidosis can still be present even when measured ketones appear normal, particularly in the clinical scenario you describe with bicarbonate of 14 mmol/L and glucose of 21 mmol/L (380 mg/dL). This represents a critical diagnostic pitfall that can delay appropriate treatment.
Why This Happens: Key Mechanisms
The disconnect between "normal" ketone measurements and true DKA occurs through several mechanisms:
Measurement Limitations
Blood ketone meters measure beta-hydroxybutyrate (BOHB) specifically, but in DKA, the ratio of BOHB to acetoacetate shifts dramatically. Early in DKA or in certain metabolic states, acetoacetate may be elevated while BOHB readings lag behind the severity of acidosis 1. The commonly used BOHB diagnostic cutoff of 3 mmol/L has poor sensitivity—studies show it cannot reliably exclude significant acidosis 1.
Poor Correlation With Acidosis
Research demonstrates that both glucose and ketone measurements correlate poorly with actual acid-base status. In one study, 22 of 133 episodes with bicarbonate <18 mmol/L were either not hyperglycemic (n=8), not ketonemic by standard thresholds (n=9), or neither (n=5) 1. BOHB showed only moderate correlation with pH (r = -0.44) and bicarbonate (r = -0.49), meaning substantial acidosis can exist despite seemingly reassuring ketone levels 1.
Euglycemic DKA Considerations
While your glucose is elevated, the principle applies: SGLT2 inhibitors, starvation states, chronic liver disease, pregnancy, and alcohol use can all produce DKA with atypical presentations where standard glucose and ketone thresholds fail 2, 3. Even during DKA treatment, inadequate glucose supplementation can perpetuate ketoacidosis despite normalizing glucose 4.
Your Clinical Scenario Analysis
With HCO3 of 14 mmol/L and glucose of 21 mmol/L, you have:
- Significant metabolic acidosis (normal HCO3 is 22-28 mmol/L)
- Moderate hyperglycemia
- High anion gap (presumed, though you didn't provide it)
This biochemical picture strongly suggests DKA regardless of the ketone reading 1. The bicarbonate of 14 mmol/L indicates substantial acid accumulation that must be explained.
Critical Action Points
Always obtain pH and/or bicarbonate in suspected DKA, regardless of glucose or ketone results 1. These are your definitive markers of acidosis severity.
Check for an elevated anion gap to confirm ketoacidosis versus other causes of metabolic acidosis (lactic acidosis, uremia, toxic ingestions).
Consider alternative or overlapping causes: acute kidney injury, starvation ketosis, alcoholic ketoacidosis, or SGLT2 inhibitor use may coexist with diabetic causes 5, 3.
Optimal ketone cutoffs are higher than traditionally taught: Studies suggest BOHB of 6.3 mmol/L, acetoacetate of 1.4 mmol/L, or total ketones of 8.0 mmol/L better identify true DKA 6. Standard point-of-care thresholds miss cases.
Treatment Implications
Based on current ADA guidelines 7:
- Initiate standard DKA management with IV fluids and insulin infusion
- Do NOT rely on bicarbonate therapy—it shows no benefit in DKA resolution and may worsen outcomes 7, 8
- Ensure adequate glucose supplementation once glucose drops to prevent persistent ketoacidosis 4
- Transition to subcutaneous insulin only after administering basal insulin 2-4 hours before stopping IV insulin 7
Common Pitfall to Avoid
The most dangerous error is dismissing DKA because ketones are "normal" or glucose isn't dramatically elevated. The acid-base status (pH and bicarbonate) defines the diagnosis and severity, not the glucose or ketone levels alone 1. In your case, treat as DKA until proven otherwise with full metabolic workup including arterial or venous blood gas.